Preview: Game #128, Diamondbacks @ Phillies

Randall Delgado RHP, 4-4, 3.82

Ethan Martin RHP, 2-2, 5.23

Diamondbacks line-up

1. Tony Campana, CF
2. Adam Eaton, LF
3. Paul Goldschmidt, 1B
4. Martin Prado, 3B
5. Aaron Hill, 2B
6. Gerardo Parra, RF
7. Wil Nieves, C
8. Cliff Pennington, SS
9. Randall Delgado, P

Well, no shortage of speed in the outfield today for the Diamondbacks: could be the fastest starting trio anywhere in the major-leagues. Would it be quicker with Pollock replacing Parra? Hard to be sure: but let's just say that range should not be an issue this afternoon, and we should hopefully not see too many balls being hit into gaps and going to the wall. That's a good thing when Delgado is on the mound, because you're probably going to see a lot of fly-balls tonight: his GB/FB ratio of 0.76 is the lowest of any of Arizona's current starting pitchers, and significantly below league average of 0.86.

That likely plays into why Delgado's HR rate is the highest in the rotation, with 4.1% of plate appearances so far ending in a home-run for the opposition. He allows a good number of fly-balls, and the rate at which they become home-runs is also higher than normal: 10.6% compared to league average of 7.2%. This number should end up regressing toward the mean over the long term, but fly-ball pitchers do tend to be prone to the long-ball, and so that's something that will always have the potential to bite him. Making sure that he keeps runners off base, with a low walk-rate, will help minimize the damage.

Could do with the offense waking up a bit. Over the six games we've played since the 15-run outburst against the Pirates, the Diamondbacks have averaged 3.8 runs per contest, with an OPS of .638. They haven't been showing much plate discipline, averaging barely two walks per game, with 13 BB in the 247 plate-appearances. Interesting to break down how walk-rate has played in to the team's overall W/L record this season, because it does seem to have a significant impact on our overall W%. In some ways, that's obvious: good things happen when you get on base, as Mark Grace should have been saying. But the difference is striking:

• 0-2 walks: 20-33 (.377 win percentage)
  
• 3-4 walks: 24-21 (.533)
  
• 5+ walks: 21-8 (.724)

Of course, it's a little difficult to tell whether this is correlation or causation. It could be that good opposing pitchers, whom we aren't likely to beat to begin with, don't walk many people. You don't initially find the same kind of correlation - albeit in the opposite direction - when you look at our results by strikeout:

• 0-5 strikeouts: 25-13 (.658 win percentage)
• 6-8 strikeouts: 19-31 (.380 win percentage)
• 9+ strikeout: 21-19 (.539 win percentage)

However, we should factor in that these counting stats apply to extra-inning games, which are more likely to rack up high numbers of both strikeouts and walks, and where the Diamondbacks have been fairly dominant, posting a 13-5 record this year. I'd probably have to restrict it, just to regulation contests, to see if there's any more of a correlation. However, I'm out of time, so that'll have to wait for another preview!